single frame vs prepass animation.

V-Ray for 3ds Max V-Ray for 3ds Max :: General
1

I’ve got a scene with moving objects. As per the spot3d tutorial I’ve done a irradiance map animation ‘prepass’ and also set light cache to ‘single frame’.
Once all is calculated, i change irrandiance map to animation ‘render’ and turn off light cache in the secondary engine.

Now all renders just fine and looks as it should, however the rendered frame takes about double the time as say a normal frame that doesn’t use a precalculated iradd & Lcache. Have I done something wrong or missed an important step here?

Cheers.

2

you only need the Irmap and none for secundary bounces if you are not using LC for glossy refl.
have you try using BF instead?

3

yes i have tried BF , quite a bit slower. really not sure what is going on here as I would have thought the precalc imap would behave somewhat the same as say one that’s calculated just before rendering. Perhaps something to do with imap interpolation between frames?

4

it is becasue in animation step irridiance maps are blended together (it think that default value is set to 2 which I think means that it is taking to frames before and to after into consideration).

Best Regards
Tomek

5

mm surely the interp between frames shouldn’t be making a 4minute render into an 8 minute one? I must be doing something wrong here.

6

and yet…try to lower the value to one to 1, that will help in rendering time and you might get flickering free solution as well.

7

in the end i tried 1 and also 0. obviously 0 produced a little bit of flicker, but render times were still higher than rendering a single frame without a precal map.

Has anyone else experienced these jumps in rendertimes in similar circumstances?

Cheers.

8

I’m guessing, maybe it’s something to do with “store direct light”

9

flino2004, you may be onto something here, will have to do some more tests and see.

10

Try dropping your Interp Samples down to 5 for the ‘Animation Rendering’ pass. It set to 20 by default, which is too high. Don’t change it for your prepass though.